Hydraulic variable-speed transmission.



C. M. CONRADSON.

HYDRAULIC VARIABLE SPEED TRANSMISSION.

APPLICATION FILED FEB. 3. 1914.

Patented FebflZ, 1918.

5 SHEETSSHEET 1.

C. M. CONRADSON.

HYDRAULIC VARIABLE SPEED TRANSMISSION.

APPLICATION FILED FEB. 3.1914.

m. MMJ w r v Q NW 2W ww w FE lw Mm n W H m 79 D... m5 w mnwsw aw L 0 JM W x? 6 1 L WW2 C. M. CONRADSON.

HYDRAULIC VARIABLE SPEED TRANSMISSION.

APPLICATION FILED FEB-3.1914.

Patented Feb. 12, 1918 5 SHEETSSHEET 3.

C. M. CONRADSON.

HYDRAULIC VARIABLE SPEED TRANSMISSION.

APPLICATION FILED FEB. 3, I914.

Patented Feb. 12, 1918.

5 SHEETSSHEET 4- C. M CONRADSON.

HYDRAULIC VARIABLE SPEED TRANSMISSION.

w s w w p M e m w r M M f my oonaan m. conaenson, or manrscn, WISCONSIN.

HYDBAUEIC VARIABLE-SPEED TRANSMISSION.

The object of my invention is to provide a gearless variable speed transmission capable of use on power propelled vehicles of various types and particularly 'designedfor automobiles or other motor vehicles.

A. further object is to provide a transmission having the functions of a differential and adapting itself automatically to the varying speeds of the vehicle carrying wheels.

A further object is to provide a trans m ssion which can be easily andquickly controlled from the drivers seat.

A further object is to provide. a hydraulic transmission of simple constructionand one which will be reliable and durable in its operation.

, Other obj"cts of the invention will appear from the following detailed description.

The invention consists generally in various constructions and combinations, all as hereinafter descr bed and particularly pointed out inthe claims.

In the accompanying drawings forming part of this specification,

Figure 1 is a side elevation of an automobile chassis with my invention i applied thereto,

Fig. 2 is a rear end view of the same,

Fig. 3 is a vertical sectional view through the rear axle transmission,

Fig. 4 is a sectional view on the line 20-41: of Fig. 3,

Fig. 5 is a sectional view on the line 2-2 of Fig. 3,

F g. 6 is a sectional view on the line y- I of Fig. 3,

Fi 7 1s a sectional view on the line H of Fig. 3, Fig. 8 is a detail sectional view illustrating'the preferred form of pump for forcing the inelastic fluid through the transmission,

Fig. 9 is a sectional view on the line 21-4) of Fig. 8.

In the-drawings, 2 represents the chassis of the car, having forward and. rear carry- Specification of Letters Patent.

Patented Fee. 12, rare.

Application filed Eebruary 3. 1914. Serial No. 816,173.

ing wheels 3 and 4. Referring now to Fig. 3, 5 represents the axle section on one end of which the carrying wheel for that side is mountedI A similar axle section on the other side I will designate by the reference numeral 5. The housing for the transmission comprises preferably a middle portion 6 and heads 7 mounted upon the axle sections and secured by suitable means, as bolts S, to the middle portion. Within the housing I provide transverse walls 9 and 10, spaced apart and having a centrally arranged hub 11 that is concentric with the axle sections. Between the walls 9 and 10 an annular chamber 12 is formed, and within the chamber 12 and encircled thereby is a chamber divided by a partition 12 into an inlet chamber 13 and an outlet chamber 13'. A pipe 14 projects through the wall of the housing into the inlet chamber 13 to supply aninelastic fluid, such as oil. thereto, as will hereinafter appear, and said pipe has a rotary movement in a suitable packing 15 interposed between it and the walls 9 and 10. A second pipe 16 is concentric with the pipe 14 and incloses the same and is spaced therefrom. and communicates with the outlet chamber 13, a packing 17 allowing rotary movement of the pipe 16, an annular passage 18 being formed between the pipes through which the inelastic fluid may flow outwardly fromthe chamber 13. lhis rotary movement of the pipes in the housing will prevent damage or breakage of the connections which might result from rocking or twisting of the car. When the drivingmechanism is set for reverse movement, the of the inelastic fluid through the pipes 14" and 16 will be correspondingly reversed,

while normally the inner pipe will conduct These mechanisms are extending from end to end, eccentrically arranged with respect to the center of. the housing and the axle sections and adapted to receive a-preferably hollow crank pin 20. Thehollow crank pin not only reduces weight, but is adapted, through the ports therein, for feeding oil to the moving parts of the mechanism. A ring 21 encircles this pin and anti-friction rolls 22 are interposed between said ring and shaft, said ring forming bearings for segments 23 provided at the inner ends of piston rods 24 having pistons 25at their outer ends in cylinders 26. The outer ends of the piston rods 24 preferably have ball and socket bearings 24' in the pistons 25, said bearings allowing the piston rods to swing and accommodate themselves to the position of the cylinders with respect to the pin 20. The piston heads are preferably formed in two parts, separated by a suitable packing. The segments 23 are heldin placeon the ring (by suitable locking rings 27. There are preferably five of these cylinders, as indicated in Fig. 7, arranged in' groups upon each side of the middle portion of the housing. The cylinders are of the same size and there are the same number in the two groups mounted on the opposite ends of the crank pin 20. Each cylinder has a removable head 28 that is ccessible through an opening 29 in the housing. Each cylinder is provided at its outer end with a port 30 communicating with a duct 31 which has a bearing surface 32 on a stationary ring 33, mounted in the wall 9 and encircling the hub 11 and provided with slots 34 which communicate successively with the ducts 31 as the cylinders 26 are revolved.

These slots 34 are arranged at intervals in the ring 33 and communicate with the chamber 13 to receive the inelastic. fluid. dis- {-37 and the spider arm. These cups, there being one foreach spider arm, receive the charged from the'pipe 14 or return this fluid to the pipe 16. A hub 35. is secured on the axle section 5 and has a series of spider arms 36 to which the cylinders 26 are secured. The hub 35 has n anti-friction bearing 37 in the housing and a thrust bearing 38 is. also provided between the bearing 37 and a" the end of the cylinder, and when the inelastic fluid is under compression therein it will flow down through the duct 43, the valve 44 i and the duct 42 and into a cup 46 that is arranged on the hub 35, between the bearing oil under compression and force the plunger f; 47 against the bearing 37 and thereby force 'the' .pump in the opposite direction to more firmly seat the valve surface 32 on the ring 33; I also prefer to provide a bearing 48' between a wall 49 of the cylinders and the hub'll. The hub 35 is free to slide on the axle section 5 andaccommodate itself to the side strain of the wheels, preventing this strain from being transmitted to and unseating the surface 32 from the ring 33.

As indicated in Fig. 6, the inner chamber is provided with partitions 50 and 51, dividing the space into an inlet chamber 13 which communicates with the pipe 14 and an outlet chamber 13, which communicates with the pipe 16. The wall 12, separating the inlet and outlet chambers from one another, is provided with a port 53 through which the inelastic fluid may flow into the pipe 16. The chambers 13 and 13', as indicated in Figs. 3 and 6, are encircled by the chamber 12 that is adapted to contain a supply of oil and a relief valve 54' is provided in the wall of the outlet chamber to allow the escape of any overplus of oil into the chamber 12 should the pressure therein become excessive, while the second valve 55,

, provides for the intake ofoil to the outlet chamber in case the volume or pressure falls below the desired point or pipes are not full of oil. When the inelastic fluid flows into the inlet portion of the chamber 13 and from thence passes through the ducts 31 into the cylinders, the pressureon the pistons in the cylinder heads will cause rotation of the cylinders and as they revolve around their axis the pistons will be alternately moved back and forth in the cylinders to admit the oil or expel it therefrom. The movement of the pistons will be timed so that'when a duct 31 is passing the inlet port of the ring 33 the passage into the cylinders will be exposed to allow the flow of the fluid therein and correspondingly all passages and ports will be opened on the return stroke of the piston to permit the expulsion of the fluid from the cylinder, the

,two sets or groups of cylinders operating {independently of one another nd evidently, if'for any reason one wheel of the car is moving more rapidly than the other wheel,

the group of cylinders connected with the axle of the faster running wheel will receive a greater quantity of the fluid and their pistons will operate at a correspondingly greater speed and thereby have all the functions of a difl'erential gearing to compensate for any variation, in the speed of the wheels, as in turning'the machine. The

device will thus not only act as a-transmission between the source of power and the carrying wheels, but will automatically compensate for the difference in travel of. the Wheels. 'The inelastic fluid is free to flow equally to the cylinders of the motors, or it may flow unequally, if'the capacity of one group ot'cylinders is greater through increase of speed than the other group. This may be a temporary condition, and when the speed of the wheels, becomes uniform the pistons have a fixed strokeunder all conditions.

As a suitable. source of motive power I provide an engine 56 mounted on the forward portion of the chassis and having a driving shaft 57. (See Fig. 8). On this shaft is keyed a hub 58. A housing 59 is secured to the engine bed and spiders 60 radiate from said hub and support a group of cylinders 61. Between the housing and the spiders a thrust bearing and cups to receive the fluid pressure from ducts in the spiders are provided, of substantially the same form as heretofore described with reference to Fig. 3, and which I will designate by the same reference numerals. The cylinders have ports corresponding to those of the cylinders in Fig. 3, with ducts leading thereto from slots in a ring which I will designate by the same reference numerals, the slots in said ring communicating with pipes 62 and 63 leading to a head 64 that is pivoted at 65 and in which the concentric ends of the pipes 14 and 16 are secured. The pistons 66 in these cylinders have stems corresponding to those described and mounted in a similar manner upon a stud 67 having a T-head 68 that is provided with a threaded socket to receive a screw 69 mounted in bearings in the housing and provided with a pinion 70. The stem 67 has a radial movement in a guide 71, being actuated back and forth therein by the movement of the head 68 when the screw 69 is revolved. Any suitable mechanism may be employed for operating. this T-heati, but I prefer to mounta wheel 72 on a sleeve 73 that is concentric with the steering post 74,. provided with a gear 75 which hasa [wheel- 7 2 convenient driving connection with the pinion through a gearing 76. Vith this mechanism the driver of the car will have the to the steering wheel 77 and whenever desired, can revolve the screw 69 and move the stem 67 toward or from the -center of the driving shaft to increase or decrease the stroke of the pistons. Obviously, if the stem 67 is concentric with the driving shaft, the pistons will have no motion whatever and with their cylinders.

will act as a fly wheel. By shifting the stem 67 off the center of the drivingshaft, the supply of inelastic fluid will be set in motion and forced through the pipe 14 to the motors and returned thereby through the pipe-16 to the cylinders 61. As before stated, the stroke of the motors is fixed, while that of thepiston's '67 will be variable,

. said pump.

and hence the driver of the car, by regulatand quickly control the speed of the car.

From the foregoing it will be noted that the two axle motors forming the differential, and the variable stroke pump connected with the source dfpower, have duplicate parts except for the crank pin on which the two axle motors are mounted, and that the eonstruction'is extremely simple and at the same time strong and durable and capable of withstanding the jolts and hard usage to which the transmission apparatus of an automobile is usually'subjected.

In the operation of the apparatus, the driver. of the car, if desiring to go forward, will move the T-head of the pump off the center of the drive shaft toward the position indicated in Fig. 8, whereupon the movement of the pump pistons will drive the inelastic fluid, such as oil, backwardly through the pipe 14 and into the cylinders of the I motors, and'returning'through thepipe 16. If the car is moving straight ahead, the oil will flow equally to the cylinders of. the motors, but if turning, the oil will flow unequally, one motor receiving a greater portion than the other to compensate for the difference in speed of the wheels. The degree of movement of the T-head from the center of the shaft 57 will, of course, determine the speed of the machine. Whenever desired, the T-head may be moved to the opposite side of the center of the shaft and the direction of movement of the machine will be reversed. l

I claim as my mventionz 1. The combination, with rear axle sec tions and carrying wheels, of hydraulic transmission motors operatively connected with said sections respectively, 'a hydraulic pump having a variable stroke and supply and return pipe connections with both of said'motors, a source of motive power for said pump, said motors having ducts provided with bearing faces and pressure and exhaust chambers having slotted openings with which said ducts register as the motors revolve, and valve rings having slotted openings therein contacting with the bearing faces of said ducts.

2. The combinati-on, with the rear axle sections and carrying wheels, of hydraulic transmission motors having fixed strokes arranged side by side and connected respectively with said sections, a hydraulic pump, supply and return pipe connections with both of said transmission motors, a hub interposed between said motors and having bearings therefor and provided with chambers communicating with said supply and return pipe connections, said motors having ducts for communication with said chambers, and a source of motive power for 3. The combination, with a vehicle chassis having forward and rear carrying wheels and rear flXlBSGCtlOIlS whereon sald rear wheels are mounted,a housing inclosing the abuttingends of said sections and provided with a hub concentric with said sections, motors j ournaled on said hub and connected with said axle sections for independr em revolution, said motors having ducts communlcat ng with chambers provided 1n said housing, a pump mounted on the forward portion of said chasis and means for operating said pump and plpeconnectlons between said pump and said housing cham- I bers. v r

,4. The combination, with axle sections and carrying wheels, of motors mounted to revolve with said sections, each comprising a plurality of cylinders concentrically mounted with respect to said axle sections and pistons eccentricallyimounted with respect to said sections, ahousing for said motors haV-,

a ing inlet and outlet chambers, a fluid supply and return pipes communicating respectively with said chambers, stationary valve rings having slotted openings therein communicating with said chambers respectively, said cylinders having fluid ducts provided with hearing faces to lide on said rings, and intake openings to communicate with ,said slotted openings successively as said motors 'revolve, and means for forcing a fluid through said pipes and cylinders to'revolve said motors and sa d axle sec ioh '5. The combination, with axle sections and carrying wheels, of motors mounted to revolve with said sections and eacji comprising cylinders concentrically mounted with respect to said axle sections, and pistons eccentrically mounted with respect to said sections, a housing for said motors having inlet and outlet chambers, fluid supply and return 1 pipes communicating respectively with said chambers, each of said cylinders havmg a fluid duct communicating therewith, rings I having slotted openin'gs communicating respectively with said chambers and successively with said ducts as 'said cylinders are revolved, means for forcing a fluid vthrough said pipes and said cylinders to revolve said \motors the-bearings of said motors on the opposite side thereof from said fluid ducts.

having meanscommunicating; with said comprising cylinders concentrically arranged with'respect to said hub and pistons eccentrically mounted with respect thereto, said housing having inlet and outlet chambers, said cylinders having fluid ducts com- A municating therewith and'with slotted openings leading to said chambers, fluid supply and return pipes for said chambers, and

axle sections, said housing having a hub con-.

centric with said sections, of motors journaled on said hub, hubs splined on said axle sections and having spider arms secured to said motors, said motors having cylinders concentrically mounted with respect to said hub, and pistons eccentrically mounted with respect thereto, said housing having inlet and outlet chambers and fluid supply and return pipes therefor, said cylinders having fluid supply ducts leading thereto and seats for said'ducts adjacent to said chambers and provided with slotted openings communicating with said chambers, said spider arms having fluid ducts therein communicating with said cylinders, and bearings for the hubs of said spider arms having cups communicating with said spider arm ducts to receive a fluid therefrom for holding said cylinder ducts against their slotted; seats, and means for forcinga fluid through said pipes, said chambers, said cvlinders and said ducts to revolve said chambers.

8. The combination, with a chassis having forward and rear carrying wheels and rear axle sections, and a hub concentric with said sections and provided with supply and-relief chambers, motors connected with said axle sections respectively and mounted on said hub and comprising cylinders and/pistons thereforQand ducts positioned to communicate with said supply and relief chambers as said cylinders are revolved, a pump mounted on the forwardportion of saidchassisand' having pipe connections with said supply and relief chambers, and means for operating saidpump.

9. The combination, with a housing having a hub therein, and inner and outer chamber encircling said hub, one of said cham bers forming an inelastic fluid supply and relief chamber, the other, of saidchambers being divided into an inlet and anoutlet chamber, supply and return p1pes communieating with sald inlet and outlet chambers respectively, the wall of said inner chamber havingrvalved. supply and relief .ports' therein, motors j'ournaled on saidhub and having cylinders concentrically arranged with respect thereto, pistons for said cylinders e05; centrlcally arranged with respect to said hub, axle sectionsconcentric with saidhub and operatively connected with said motors,

said cylinders having fluid ducts communieating with said inlet and outlet chambers successively as said motors are revolved, and

means for forcing an inelastic fluid through said pipes and chambers and said cylinders.

10=The combination, with a housing, of revolving motors journaledtherein, axle sections operatively connected with said motors to be revolved thereby, said housing having inelastic fluid inlet and outlet chambers communicating with said motors, supply and return pipes for said chambers respectively, means for forcing an inelastic fluid through said pipes and chambers to'said motors, said pipes having a rotary movement in their bearings in said housing at one end and a pivotal connection with said forcing means at their other end.

11. The combination, with a housing, of revolving motors journaled therein, axle sections operatively connected with said motors, inelastic fluid pipes concentrically mounted in said housing at one end and communicat ing with said motors, said pipes being spaced apart to form a circulating passage between them and having a rotary movement in their b r gs in said: housing, means for forcing an inelastic fluid through said pipes and motors, said forcing means having a pivotal connection with said pipes, for the purpose specified. V

12. The combination, with a chassis having. forward and rear carrying wheels, axle sections for said rear wheels, revolving motors connected with said sections respectively and comprising cylinders and pistons there for and fluid ducts leading to said cylinders, means having bearings for said motors and supply and exhaust chambers positioned to communicate'withsaidducts as said cylinders are revolved, fluid pressure supply and return pipes communicating with said chambers, a source of motive power mounted on the forward portion of said chassis for forcing'the fluid through said pipes and motors, for the purpose specified.

13. The combination, with a chassis having forward and rear carrying wheels and rear axle sections, of motors comprising revolving cylinders and pistons therefor connected respectively with said axle sectlons and having fluid pressure ducts, means having fluid pressure supply'and relief chain: bers interposedbetween saidaxle sectlons for communication with said fiuld pressure ducts as said cylinders are revolved, a fpuma mounted on the forward portion 0 a chassis and having pipe connections with said supply and relief chambers, said pump including cylinders and pistons, and means within control of thedriver for varying the stroke of said istons to increase or decrease the flow of fluid through said pipes.

17-1. The combination, with a housing, of

revolving motors journaled therein, axle secsupply and return pipes concentrically arranged and .communicating with said motors, said pipes being spaced apart to form a circulating passagebetween them, means for forcing an inelastic fluid through said pipes and motors, said pipes having a longi-. tudinal and a rotary movement in their bearings, for the purpose specified.

15. The combination, with a chassis havmg forward and rear carrying wheels and rear axle sections, of motors mounted to revolve with saidsections and comprising cyl 'inders and pistons therefor, relatively eccentric and concentric with respect to said sections, said pistons having a fixed stroke with respect to said cylinders, a housing having fluid supply and'relief chambers between said motors and said motor cylinders having fluid ducts for communication with said chambers, fluid supply andc return pipes for said chambers, a pump mountedton the forward portion of said chassis and communiv eating with said fluid supply and return pipes, the pistons-of said ump having a variable stroke, and means or shifting said pistons to increase or decrease the stroke thereof and the flow of said fluid through said pipes.

v 16. The combination, with a housing and axle sections therefor and a hub concentric with said sections, of motors connected with said sections and having bearings on said hub and comprisin cylinders and pistons therefor, said -hub h chambers, said motors having fluid ducts chambers, fluid supply and return pipes for said chambers, means for forcing the fluid through said pi es and chambers and said cylinders to revo ve said motors.

\ 17. The combination, with a housing and aving inlet and outlet communicating therewith and with said axle sections therein, said housing having a hub concentric with said sections, of motors means for forcing a fluid through said pi es and chambers and said cylinders to revo ve' 18. The combination, with a housing, of revolving motors journaled therein, axle sections having carrying wheels operativelyconnected withisaid motors, fluid supply and return pipes concentrically arranged and communicating with said motors, said pipes pipes and motors, said pipes having a lonbeing spaced apart to form a circulating pasgitudinal and a rotary movement in their sage betweenthem, and means for forcing bearings. a fiuid through said pipes and motors. I In witness whereof I have hereunto set my 5. 19. The combination, with a housing, of hand this 29" day of January, 1914. revolving motors journaled therein, axle sections having carrying Wheels operatively CONRAD CONRADSON' connected with said motors, fluid supply and Witnesses: I

return pipes communicating With said mo- GENEVIEVE E. SoRENsEN,

1p tors, means for forcing a fluid through said EDWARD A. PAUL. 

